This invention relates to irrigation sprinklers, and more particularly, to a new and improved sprinkler construction for sprinklers of the type generally referred to as "spinners".
There are many different types of rotary sprinkler constructions used for irrigation purposes, including impact or impulse drive sprinklers, motor driven sprinklers, and rotating reaction drive sprinklers. Included in the category of rotating reaction drive sprinklers are a species of sprinklers known as a "spinner" and which has found particular application in the irrigation of agricultural crops and orchards.
Typically, such spinner type sprinklers comprise a stationary support structure or "bridge" which is adapted to be coupled with a supply of pressurized water, and a rotating sprinner drive supported by the bridge for rotation about a generally vertical axis. Most spinner type sprinklers employ either a rotating reaction drive nozzle to form the spinner device, or employ a fixed nozzle which ejects a stream of water vertically onto a rotating deflector which redirects the stream into a generally horizontal spray, the deflector being rotated by a reaction force created by the impinging stream from the fixed nozzle. Exemplary of such prior art spinner type sprinklers are those disclosed in U.S. Pat. Nos. 4,356,972; 4,440,345; 4,498,628; 4,660,766; 4,796,811; and 5,007,586.
One problem that has been encountered with spinner type sprinklers is that due to a very high rate of rotation of the spinner devices, the distance water is thrown from the sprinkler may be substantially reduced. To correct this problem, the prior art has recognized that brake mechanisms, typically employing the principle of viscous fluid shear, can be added to the sprinkler to very substantially reduce the rate of spinner rotation, thereby increasing the area covered by the sprinkler. Such brake mechanisms are disclosed, for example, in the spinner type sprinklers of the aforementioned U.S. Pat. No. 4,440,345 relating to a rotary nozzle type spinner, and U.S. Pat. No. 4,660,766 relating to a fixed nozzle with rotating deflector type spinner.
The present invention is directed to a new and improved construction for a spinner type sprinkler, particularly of the type employing a rotating reaction drive nozzle, which significantly increases the operational range and capabilities of such sprinklers, and provides a substantial increase in performance over prior art spinners, particularly over such spinners employing fixed nozzle with rotating deflector type constructions.